Roller bearing device and method of lubricating roller bearing

ABSTRACT

A bearing device includes a lubricating device that supplies a lubricant to a first lubricating path when a rotating speed of an inner ring member is detected to be no more than a predetermined speed and supplies the lubricant to the first lubricating path and a second lubricating path when the rotating speed of the inner ring member is detected to be higher than the predetermined speed, the lubricating device including a changeover valve that controls a supply of the lubricant to the first and second lubricating paths according to the rotating speed of the inner ring member.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present Application is a Divisional Application of U.S. patentapplication Ser. No. 10/829,990 filed on Apr. 23, 2004. The presentApplication is based on and claims priority to Japanese patentapplication No. 2003-122480, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a roller bearing device, for example,used for a main shaft of a machine tool. The present invention alsorelates to a method of lubricating the roller bearing.

A tapered roller bearing device is known in which the generation ofheat, which is made in the bearing when the bearing is rotated at highspeed, is reduced. The tapered roller bearing device is disclosed inPatent Document 1 for example.

This tapered roller bearing device includes a hole penetrating the innerring member in the axial direction and a hole penetrating the inner ringmember from the hole in the radial direction. This hole is used as anoil supplying hole. A first nozzle from which pressured oil is injectedis provided in the outer ring spacer while the first nozzle is opposedto an opening of the oil supplying hole. A through-hole penetrating theinner ring spacer in the axial direction is arranged in thecircumferential direction alternately with the hole in the axialdirection, and a second nozzle, which is open being opposed in thebearing, is provided in the outer ring spacer.

Oil injected from the first nozzle is supplied into the hole of theinner ring member formed in the axial direction. This oil flows outwardby a centrifugal force generated by the rotation of the inner ringmember and is supplied to a sliding contact portion between the largeend face and the inner ring flange face which is a portion from whichheat is generated at the maximum. Therefore, this oil deprives thesliding contact portion of generated heat. A portion of the oil injectedfrom the first nozzle deprives the inner ring member of generated heatwhen the oil flows in the penetrating hole of the inner ring member. Theoil injected from the second nozzle enters the inside of the bearing andlubricates a rolling contact face inside the bearing.

Patent Document 1

JP-A-8-270660

According to the tapered roller bearing device, heat generated when thetapered rollers are rolling can be removed, and the rolling contact facecan be lubricated. However, according to the technique of the taperedroller bearing device, it is impossible to lubricate the inside of thebearing according to the rotating speed of the inner ring member.Therefore, under certain circumstances, an unnecessarily large quantityof lubricating oil is supplied to the bearing, and the stirringresistance of the rollers is increased.

SUMMARY OF THE INVENTION

Accordingly, it is desired to accomplish the technique of preventing thestirring resistance from increasing and suppressing the generation ofheat quickly according to the rotating speed of the inner ring member.

In order to solve the aforesaid object, the invention is characterizedby having the following arrangement.

(1) A bearing device comprising:

an inner ring member through which a shaft is passed and which issupported rotatably about an axis of the shaft and includes an innerring raceway surface;

an outer ring member arranged concentrically with the inner ring memberand including an outer ring raceway surface;

a plurality of rollers arranged rollably between the inner ring racewaysurface and the outer ring raceway surface;

a lubricating path through which lubricant is supplied to at least oneof the inner ring raceway surface and the outer ring raceway surface;and

a lubricating device which supplies the lubricant to the lubricatingpath according to rotating speed of the inner ring member about theaxis.

(2) The bearing device according to (1), wherein

the lubricating path includes first and second lubricating paths, and

the lubricating device includes a rotation detector for detecting therotating speed of the inner ring member, a changeover valve deviceconnected to the first and second lubricating path and a controller forcontrolling the changeover valve device according to a detecting resultof the rotation detector.

(3) The bearing device according to (2), wherein the controller controlsthe changeover valve device so that the lubricant is supplied to one ofthe first and second lubricating paths when the rotating speed of theinner ring member is no more than a predetermined speed, and is suppliedto the first and second lubricating paths when the rotating speed of theinner ring member is higher than the predetermined speed.(4) A method of lubricating a bearing device including an inner ringmember through which a shaft is passed and which is supported rotatablyabout an axis of the shaft and includes an inner ring raceway surface,an outer ring member arranged concentrically with the inner ring memberand including an outer ring raceway surface, a plurality of rollersarranged rollably between the inner ring raceway surface and the outerring raceway surface, and a lubricating path through which lubricant issupplied to at least one of the inner ring raceway surface and the outerring raceway surface, the method comprising the steps of:

detecting a rotating speed of the inner ring member about the axis; and

supplying the lubricant to the lubricating path according to thedetected rotating speed of the inner ring member.

(5) The method according to (4), wherein

the lubricating path includes first and second lubricating paths, and

the lubricant is supplied to one of the first and second lubricatingpaths when the rotating speed of the inner ring member is no more than apredetermined speed, and is supplied to the first and second lubricatingpaths when the rotating speed of the inner ring member is higher thanthe predetermined speed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial sectional view of the machine tool main shaft inwhich the roller bearing of the first embodiment of the presentinvention is used.

FIG. 2 is an enlarged sectional view of the primary portion of FIG. 1.

FIG. 3 is a partial sectional view of the machine tool main shaft inwhich the roller bearing of the second embodiment of the presentinvention is used.

FIG. 2 is an enlarged sectional view of FIG. 3.

FIG. 5 is a partial sectional view of the machine tool main shaft inwhich the roller bearing of the third embodiment of the presentinvention is used.

FIG. 6 is an enlarged sectional view of FIG. 4.

FIG. 7 is an enlarged sectional view of the roller bearing device shownin the fourth embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, examples of the roller bearing deviceaccording to the embodiment of the present invention will be describedbelow when a roller bearing device for supporting a drive shaft of amachine tool is taken up as an example.

First Embodiment

The first embodiment of the present invention will be explained below.FIG. 1 is a partially sectional view showing a portion of the machinetool in which a roller bearing according to the first embodiment of thepresent invention is used. FIG. 2 is an enlarged sectional view showinga primary portion of FIG. 1.

The roller bearing 1 of this embodiment is a cylindrical roller bearing.In this embodiment, a pair of cylindrical roller bearings 1 are arrangedon opposite sides in the axial direction of the drive shaft 2 of themachine tool so that the drive shaft 2 can be rotatably supported. Thestructure of the bearing on one side is the same as the structure of thebearing on the other side. Therefore, the bearing 1 on one side is shownin FIG. 2.

As shown in FIG. 1, the roller bearing 1 includes: an inner ring member4, into which the drive shaft 2 is press-fitted, and which is supportedrotatably about the axis 3; an outer ring member 5 arrangedconcentrically with the inner ring member 4; a plurality of cylindricalrollers 8 arranged between the inner ring raceway surface 6 of the innerring member 4 and the outer ring raceway surface 7 of the outer ringmember 5 in such a manner that the cylindrical rollers 8 can be freelyrolled; and a cage 9 having pockets 9 a for holding these cylindricalrollers 8 at regular intervals in the circumferential direction.

The outer ring member 5 is arranged and fixed to the innercircumferential face of the housing 10. The shoulder portions 15, thediameters of the outer circumferential faces of which are larger thanthe diameter of the inner ring raceway surface 6, are formed on oppositesides of the inner ring raceway surface 6 of the inner ring member 4 inthe axial direction. The cylindrical outer ring spacer 16 is interposedbetween the outer ring members 5, and the inner ring spacer 17 isinterposed between the inner ring members 4.

As the drive shaft 2 is rotated about the axis 3, the inner ring member4 rotates about the axis 3, and the cylindrical rollers 8 roll betweenthe inner ring raceway surface 6 and the outer ring raceway surface 7.In order to reduce an increase in the stirring resistance so as toprevent the generation of heat and the occurrence of seize due to therolling of the cylindrical rollers 8 between the inner ring racewaysurface 6 and the outer ring raceway surface 7, the inside of thebearing must be lubricated.

Then, explanations will be made to the lubricating device 20 provided inthe roller bearing 1. This lubricating device 20 includes a lubricantsupply path arranged on the roller bearing 1 side of the outer ringspacer 16. This lubricant supply path includes a first lubricant supplypath 21 and a second lubricant supply path 22.

As shown in FIG. 2, the first lubricant supply path 21 and the secondlubricant supply path 22 respectively include: the large diameter paths23, 24 formed in the outer ring spacer 16 in the radial direction; andthe small diameter paths 25, 26 formed in the axial direction in theouter ring spacer 16 from the inward end portions in the radialdirection of the large diameter paths 23, 24 to the roller bearing side.

The large path 24 of the second lubricant supply path 22 is longer thanthe large path 23 of the first lubricant supply path 21. The end portionof the small diameter path 25 of the first lubricant supply path 21 isarranged close to the outer ring member 5 in such a manner as to beopened toward the inner circumferential face end portion of the outerring member 5 in the axial direction. The end portion of the smalldiameter path 26 of the second lubricant supply path 22 is arrangedclose to the inner ring member 4 in such a manner as to be opened towardthe outer circumferential end portion of the inner ring member 4 in theaxial direction.

As shown in FIG. 1, a first supply path 30 and a second supply path 31,which are respectively connected with the first lubricant supply path 21and the second lubricant supply path 22, are formed in the housing 10.The lubricating device 20 includes a supply control device 36 forsupplying lubricating oil 35 (oil and air) into the first supply path 30and the second supply path 31.

This supply control device 36 includes: a rotation detector 37 fordetecting the rotating speed of the inner ring member 4; a changeovervalve device 38 connected to the first supply path 30 and the secondsupply path 31; a control unit 39 electrically connected to the rotationdetector 37 and the changeover valve device 38; and a lubricant supplypump 40.

Concerning the control unit 39, for example, a common one-chipmicrocomputer is used for the control unit 39 which includes: achangeover unit 41 for outputting a changeover signal to the changeovervalve device 38 according to a rotating speed signal sent from therotation detector 37; and a drive unit 42 for outputting a drive signalto the drive portion of the lubricant supply pump 40. As describedabove, the roller bearing device is composed of the roller bearing 1 andthe lubricating device 20.

Next, lubricating operation of lubricating the roller bearing 1 will beexplained below. The rotation detector 37 detects the rotating speed ofthe drive shaft 2 at all times while the machine tool is being driven.The thus detected rotating speed is outputted into the changeover unit41 of the control unit 39 and also outputted into the drive unit 42.Further, a drive signal is outputted from the drive unit 42 into thedrive portion of the lubricant pump 40.

In the case where the rotation detector 37 detects a rotating speedsignal representing the rotating speed not more than a predeterminedspeed, that is, in the case where the inner ring member 4 (drive shaft2) is rotating at a low rotating speed, the changeover unit 41 outputs adrive signal to the drive portion of the lubricant supply pump 40 viathe drive unit 42, and the changeover unit 41 outputs a drive controlsignal to the drive portion of the changeover valve device 38 so thatthe lubricating oil 35 can be supplied to the first supply path 30 andthe supply of the lubricating oil 35 to the second supply path 31 can beshut off.

Therefore, in the case where the inner ring member 4 is rotating at alow speed, the lubricating oil 35 is supplied from the lubricant supplypump 40 into the first lubricant supply path 30 and the first lubricantpath 21 via the changeover valve device 38. Therefore, the lubricatingoil 35 is supplied from the opening of the first lubricant path 21toward the outer ring raceway surface 7 side so that the inside of theroller bearing 1 can be lubricated by an appropriate quantity oflubricating oil 35.

In this connection, in the case where the rotation detector 37 detects arotating speed signal representing the rotating speed higher than apredetermined rotating speed, that is, in the case where the inner ringmember 4 is rotating at a high speed, the changeover unit 41 outputs adrive signal to the drive portion of the lubricant pump 40 via the driveunit 42, and the changeover unit 41 outputs a drive signal to the driveportion of the changeover valve device 38 so that the lubricating oil 35can be supplied to the first supply path 30 and the lubricating oil 35can be also supplied to the second supply path 31.

Therefore, in the case where the inner ring member 4 is rotating at highspeed, the lubricating oil 35 is supplied from the lubricant supply pump40 into the first supply path 30 and the first lubricant supply path 21via the changeover valve device 38. Therefore, the lubricating oil 35 issupplied from the opening of the first lubricant supply path 21 towardthe outer ring raceway surface 7. At the same time, the lubricating oil35 is supplied from the opening of the second supply path 31 and thesecond lubricant supply path 22 toward the inner ring raceway surface 6.In virtue of the foregoing, the inside of the roller bearing 1 can belubricated by a quantity of lubricating oil 35 appropriate for the highspeed rotation.

In this connection, when the rotation detector 37 detects that therotating speed has changed from the high speed to the low speed, thesignal is output to the changeover valve device 38 via the drive unit42, and the changeover valve device 38 can be changed over so that thesupply of the lubricating oil 35 to the second supply path 31 can beshut off. At the same time, the changeover valve device 38 is changedover so that only a current of air not containing the lubricating oil 35can be supplied into the second supply path 31 for a predeterminedperiod of time.

Then, the current of air not containing the lubricating oil 35 isdischarged from the opening of the second lubricant supply path 22.Therefore, the lubricating oil 35 sticking onto the inner ring racewaysurface 6 or the outer circumferential face of the inner ring racewaysurface 4 is discharged outside the roller bearing 1 being blown by thecurrent of air. In virtue of the foregoing, a quantity of lubricatingoil 35 appropriate for the rotation of low speed can be ensured insidethe roller bearing 1, and an increase in the temperature of the racewaysurface of the roller bearing 1 can be suppressed and the occurrence ofseize can be prevented.

As described above, according to the first embodiment of the presentinvention, a portion to which the lubricating oil 35 is supplied isselected according to the rotating speed of the inner ring member 4, anda necessary quantity of lubricating oil 35 can be supplied. Accordingly,an increase in the stirring resistance of the roller bearing 1 and arise in the temperature of the raceway surface can be suppressed and theoccurrence of seize can be prevented.

Second Embodiment

Next, referring to the sectional view of FIG. 3 and the enlargedsectional view of FIG. 4, the second embodiment according to the presentinvention will be explained below. The roller bearing of the secondembodiment of the present invention includes: an outer ring member 5; aninner ring member 4; a plurality of cylindrical rollers 8; and a cage 9.The structure of the inner ring member 4 is the same as that of thefirst embodiment. Therefore, same reference marks are used to indicatelike parts, and the explanations are omitted here.

The cage 9 has annular portions 9 b to be guided which are protrudedoutside in the radial direction and arranged on opposite sides of thepockets 9 a in the axial direction. This cage 9 is an outer ring guidecage in which the outer circumferential faces 9 c of the portions 9 bare guided by the inner circumferential face of the outer ring member 5.

Next, the lubricating device 20 will be explained below. The lubricatingdevice 20 includes lubricant supply paths 45 which are formed in theradial direction at predetermined positions of the outer ring member 5in the circumferential direction. These lubricant supply paths 45 areformed in the radial direction in portions of the outer ring member 5 insuch a manner as to be opposed to and agree with the portions 9 b to beguided in the axial direction. Accordingly, two lubricant supply paths45 are formed in such a manner as to form a pair in the axial direction.

The lubricating device 20 has a lubricant supply path 46 formed in theouter ring spacer 16. This lubricant supply path 46 includes: a largediameter portion 47 formed in the outer ring spacer 16 in the radialdirection; and a small diameter portion 48 formed from the inward endportion in the radial direction of this large diameter portion 47 towardthe outer circumferential face side of the inner ring member 4 of theroller bearing 1.

In the housing 10, first supply paths 49 and a second supply path 50,which are respectively communicated with the lubricant supply paths 45and 46, are formed. The lubricating device 20 has the supply controlunit 36 for supplying the lubricating oil 35 (oil and air) to the firstsupply path 49 and the second supply path 50.

Next, different points of the supply control unit 36 of the secondembodiment from the supply control unit 36 of the first embodiment willbe explained below. The changeover valve device 38 of the secondembodiment has the constitution in which, according to a signal sentfrom the changeover unit 41, either first supply path 49 or secondsupply path 50 is selected or both the first supply path 49 and thesecond supply path 50 are selected, so that the first supply path 49 orthe second supply path 50 can be supplied with the lubricating oil 35 orboth the first supply path 49 and the second supply path 50 can besupplied with the lubricating oil 35. Other points of this embodimentare the same as those of the first embodiment described before.Therefore, same reference marks are used to indicate like parts, and theexplanations are omitted here.

In the above constitution, in the case where the rotation detector 37detects a rotating speed signal representing the rotating speed not morethan a predetermined speed, that is, in the case where the inner ringmember 4 (drive shaft 2) is rotating at a low rotating speed, thechangeover unit 41 outputs a drive signal to the drive portion of thelubricant supply pump 40 via the drive unit 42, and the changeover unit41 outputs a drive control signal to the drive portion of the changeovervalve device 38 so that the lubricating oil 35 can be supplied to thefirst supply path 49 and the supply of the lubricating oil 35 to thesecond supply path 50 can be shut off.

In the case where the inner ring member 4 is rotating at a low speed,the lubricating oil 35 is supplied from the lubricant supply pump 40into the first supply path 49 and from the opening of the lubricantsupply path 45 to the outer circumferential face 9 c of the portion 9 bof the cage 9, that is, the lubricating oil 35 is discharged toward theface to be guided, so that the inside of the roller bearing 1 can belubricated by an appropriate quantity of lubricating oil 35.

In this connection, in the case where the rotation detector 37 detects arotating speed signal representing the rotating speed higher than apredetermined rotating speed, that is, in the case where the inner ringmember 4 is rotating at a high speed, the changeover unit 41 outputs adrive signal to the drive portion of the lubricant pump 40 via the driveunit 42, and the changeover unit 41 outputs a drive signal to the driveportion of the changeover valve device 38 so that the lubricating oil 35can be supplied to the first supply path 49 and the lubricating oil 35can be also supplied to the second supply path 50.

Therefore, in the case where the inner ring member 4 is rotating at ahigh speed, the lubricating oil 35 is supplied from the lubricant supplypump 40 into the first supply path 49 and the lubricant supply path 45via the changeover valve device 38. Therefore, the lubricating oil 35 issupplied from the opening of the lubricant supply path 45 toward theouter circumferential face 9 c of the portion 9 b. At the same time, thelubricating oil 35 is supplied from the second supply path 50 to thelubricant supply path 46. The lubricating oil 35 is discharged from itsopening toward the inner ring raceway surface 6. In virtue of theforegoing, the inside of the roller bearing 1 can be lubricated by aquantity of lubricating oil 35 appropriate for the high speed rotation.

In this connection, when the rotation detector 37 detects that therotating speed has changed from the high speed to the low speed, thesignal is outputted to the changeover valve device 38 via the drive unit42 and the lubricant supply pump 40, and the changeover valve device 38can be changed over so that the supply of the lubricating oil 35 to thesecond supply path 50 can be shut off. At the same time, the changeovervalve device 38 is changed over so that only a current of air notcontaining the lubricating oil 35 can be supplied into the second supplypath 50 for a predetermined period of time.

Then, a current of air not containing the lubricating oil 35 isdischarged from the opening of the lubricant supply path 46. Therefore,the lubricating oil 35 sticking onto the inner ring raceway surface 6 orthe outer circumferential face of the inner ring member 4 is dischargedoutside the roller bearing 1 being blown by the pressure of the currentof air. In virtue of the foregoing, a quantity of lubricating oil 35appropriate for the rotation of low speed can be ensured inside theroller bearing 1, and an increase in the temperature of the racewaysurface of the roller bearing 1 can be suppressed and the occurrence ofseize can be prevented.

Third Embodiment

Next, referring to FIGS. 5 and 6, the third embodiment of the presentinvention will be explained below. Different points of the rollerbearing device of the third embodiment of the present invention fromthose of the roller bearing of the second embodiment are explained asfollows.

The roller bearing 1 of the roller bearing device of the thirdembodiment includes shoulder portions 55, the diameter of the innercircumferential face of which is smaller than the diameter of the outerring raceway surface 7, and which is provided on opposite sides of theouter ring raceway surface 7 of the outer ring member 5. The lubricatingdevice 20 includes a pair of lubricant supply path 56, which arearranged at the boundary portions between the outer ring raceway 7 andthe shoulder portions 55, from which the lubricating oil 35 isdischarged toward the outer ring raceway surface 7. In each lubricantsupply path 56, the supply path 57 provided in the housing 10 is formed.These supply paths 57 are connected to the changeover valve device 38.Other points of the structure of the lubricating device 20 are the sameas those of the second embodiment described before.

In the above constitution, in the case where the rotation detector 37detects a rotating speed signal representing the rotating speed not morethan a predetermined speed, that is, in the case where the inner ringmember 4 (drive shaft 2) is rotating at a low rotating speed, thechangeover unit 41 outputs a drive signal to the drive portion of thelubricant supply pump 40 via the drive unit 42, and the changeover unit41 outputs a drive control signal to the drive portion of the changeovervalve device 38 so that the lubricating oil 35 can be supplied to thefirst supply path 49 and the supply path 57 and so that the lubricatingoil 35 can be supplied to the lubricant supply paths 45, 56. Further,the changeover unit 41 also outputs a drive signal to the drive portionof the changeover valve device 38 so that the supply of the lubricatingoil 35 to the second supply path 50 can be shut off.

Therefore, in the case where the inner ring member 4 is rotating at lowspeed, the lubricating oil 35 is discharged toward the outercircumferential face 9 c of the portion 9 b of the cage 9 and the innerring raceway surface 7, so that the inside of the roller bearing 1 canbe lubricated by an appropriate quantity of lubricating oil 35.

In this connection, in the case where the rotation detector 37 detects arotating speed signal representing the rotating speed higher than apredetermined rotating speed, that is, in the case where the inner ringmember 4 is rotating at a high speed, the changeover unit 41 outputs adrive signal to the drive portion of the lubricant pump 40 via the driveunit 42, and the changeover unit 41 also outputs a drive signal to thedrive portion of the changeover valve device 38 so that the lubricatingoil 35 can be supplied to the first supply path 49 and the supply path57 and so that the lubricating oil 35 can be also supplied to the secondsupply path 50.

Therefore, in the case where the inner ring member 4 is rotating at highspeed, the lubricating oil 35 is supplied to the outer circumferentialface 9 c of the portion 9 b of the cage 9, the outer ring racewaysurface 7 and the inner ring raceway surface 6, so that the inside ofthe roller bearing 1 can be lubricated by an appropriate quantity oflubricating oil 35.

In this connection, when the rotation detector 37 detects that therotating speed has changed from the aforementioned high speed to the lowspeed, the signal is outputted to the changeover valve device 38 via thedrive unit 42 and the lubricant supply pump 40, and the changeover valvedevice 38 can be changed over so that the supply of the lubricating oil35 to the second supply path 50 can be shut off. At the same time, thechangeover valve device 38 is changed over so that only a current of airnot containing the lubricating oil 35 can be supplied into the secondsupply path 50 for a predetermined period of time.

Then, a current of air not containing the lubricating oil 35 isdischarged from the opening of the lubricant supply path 46. Therefore,the lubricating oil 35 sticking onto the inner ring raceway surface 6 orthe outer circumferential face of the inner ring member 4 is dischargedoutside the roller bearing 1 being blown by the pressure of the currentof air. In virtue of the foregoing, a quantity of lubricating oil 35appropriate for the rotation of low speed can be ensured inside theroller bearing 1, and an increase in the temperature of the racewaysurface of the roller bearing 1 can be suppressed and the occurrence ofseize can be prevented.

Fourth Embodiment

Next, referring to the sectional view of FIG. 7, the fourth embodimentof the present invention will be explained below. The bearing device 1of the present invention includes a double row cylindrical rollerbearing 60, the inner ring member 4 of which has the shoulder portions.The cylindrical rollers 8, 8 are held in the pockets 9 a of the cage 9and arranged at regular intervals in the circumferential direction. Thecage 9 is an outer ring guide cage. Each cage 9 is provided with anannular portion 9 b to be guided arranged in an outward portion in theaxial direction in such a manner that the annular portion 9 b protrudesoutward in the radial direction.

In the outer ring member 5, two lubricant supply portions 45 forsupplying the lubricating oil 35 onto the outer circumferential face 9 cof the portion 9 b are formed in such a manner that the two lubricantsupply portions 45 make a pair in the axial direction. In the housing10, the supply path 62 communicating with the lubricant supply path 45is formed.

At the center of the outer ring member 5 in the axial direction, thelubricant supply path 61 for supplying the lubricating oil 35 onto theouter ring raceway surface 7 is formed in the radial direction. Thesupply path 63 communicating with the lubricant supply path 61 is formedin the housing 10. In the outer ring spacer (outer ring collar) 16, thelubricant supply path 64 for injecting the lubricating oil 35 ontoopposite sides of the outer circumferential face of the double rowcylindrical roller bearing 60 is formed. In the housing 10, the supplypath 65 communicating with the lubricant supply path 64 is formed. Thesupply paths 62, 63, 65 are connected to the changeover valve device 38.

The control unit 39 of the supply control unit 36 of the lubricatingdevice 20 drives the changeover valve device 38 so that the lubricatingoil 35 can be supplied to the supply paths 62, 63 at the time ofoperation of a low rotating speed. The control unit 39 of the supplycontrol unit 36 of the lubricating device 20 drives the changeover valvedevice 38 so that the lubricating oil 35 can be supplied to the supplypaths 62, 63, 65 at the time of operation of a high rotating speed.

In virtue of the foregoing, at the time of operation of a low rotatingspeed, the lubricating oil 35 is supplied toward the outercircumferential face 9 c of the portion 9 b of the cage 9. At the timeof operation of a high rotating speed, the lubricating oil 35 issupplied toward the outer circumferential face 9 c of the portion 9 b ofthe cage 9, the outer ring raceway surface 7 and the inner ring racewaysurface 6. In this way, the inside of the roller bearing 1 can belubricated by an appropriate quantity of lubricating oil 35.

In the case where the rotating speed is changed from high to low, thecontrol unit 39 drives the changeover valve device 38 so that thelubricating oil 35 can be supplied to the supply paths 62, 63 and sothat an air current not containing the lubricating oil 35 can besupplied for a predetermined period of time. In virtue of the foregoing,a redundant quantity of lubricating oil 35 which is supplied to theinner ring raceway surface 6 side at the time of rotating at a highspeed can be removed to a predetermined position. As shown in FIG. 1,other points of the structure of the supply control unit 36 are the sameas those of the above embodiments. Therefore, the explanations areomitted here.

As can be seen from the above explanations, in the present invention, aportion to which the lubricating oil is supplied is selected accordingto the rotating speed of the inner ring member. Therefore, the inside ofthe bearing can be lubricated in quick response by an appropriatequantity of lubricating oil. Further, it is possible to prevent anincrease in the stirring resistance of the roller bearing. Therefore, arise in the temperature of the roller bearing can be prevented.

1. A bearing device comprising: an inner ring member through which ashaft is passed and which is supported rotatably about an axis of theshaft and includes an inner ring raceway surface; an outer ring memberarranged concentrically with the inner ring member and including anouter ring raceway surface; a plurality of rollers arranged rollablybetween the inner ring raceway surface and the outer ring racewaysurface; first and second lubricating paths through which lubricant issupplied to at least one of the inner ring raceway surface and the outerring raceway surface; and a lubricating device that supplies thelubricant to the first lubricating path when a rotating speed of theinner ring member is detected to be no more than a predetermined speedand supplies the lubricant to the first and second lubricating pathswhen the rotating speed of the inner ring member is detected to behigher than the predetermined speed, said lubricating device comprisinga changeover valve that controls a supply of the lubricant to the firstand second lubricating paths according to the rotating speed of theinner ring member.
 2. The bearing device according to claim 1, whereinthe lubricating device further comprises: a rotation detector fordetecting the rotating speed of the inner ring member; and a controllerfor controlling the changeover valve according to the rotating speed ofthe inner ring member detected by the rotation detector.